Some articles of manufacture have metallic elements encased wholly or partially within brittle, non-metallic bulbs or housings. For example, reed switches commonly have two metallic elements that extend into a cylindrically-shaped vitreous bulb. A portion of each element located within the bulb constitutes a switch blade while a portion located outside of the bulb provides a connecting pin. When such reed switches become impaired or inoperative they often are discarded as waste. In some cases, however, the impaired switches are processed to reclaim their component materials.
Since the metallic components of reed switches are partially encased within glass bulbs their metallic and vitreous elements cannot be readily separated by use of gravity tables, centrifuges or the like since the elements are physically attached and fused to each other so as to provide a vacuum-tight seal. Heretofore, their component materials have been reclaimed by melting the switches and separating the vitreous material from the metal by skimming. This process however has the distinct disadvantages of being slow, costly and inefficient. It therefore would be advantageous to devise a mechanical method of separating the materials without having to melt any of the switch components.
There are mechanical devices available for fragmenting natural materials such as rocks and stones as well as for crushing articles of manufacture. These include hammers, hoppers having means for oscillating one hopper wall against another, rolling mills, hollow cylinders having impact elements housed therewithin, and rotating wheels and rollers that bear spikes, blades or teeth. For example, U.S. Pat. No. 25,371 discloses a machine having a pair of cylinders provided with peripheral teeth that rotate almost in contact with one another to crack or break up stones. This particular machine also has a funnel-shaped hopper dressed with teeth, ribs or projections that prevents stones from rising up therewithin when engaged by the cylinder teeth so that the cylinders are able to seize them. U.S. Pat. No. 3,605,243 discloses a method of removing iron and copper contaminants from zinc or aluminum base scrap wherein the base scrap is fragmented and rolled in a rolling mill so as to have a maximum thickness not greater than that of the iron or copper. The fragments are then tumbled to cause the iron or copper to break away from the zinc or aluminum. U.S. Pat. No. 4,043,019 discloses a method of removing plastic from within metallic bottle caps wherein caps are placed in a drum that has projections and which contain steel impact balls. The caps are cooled to cause the plastic to become more brittle than the metallic caps. The drum is then rotated whereupon the projections and the steel balls impact the caps and break up the brittle plastic without actually breaking the metallic caps. The plastic then may fall free from the caps. As yet another example, United Kingdom Pat. No. 1,257,394 teaches apparatus for crushing cans and bottles having a crushing zone of generally V-shaped cross-section formed by two plates. One zone plate is fixed while the other is adapted to be oscillated towards and away from the fixed plate in effecting a crushing operation.
Unfortunately, the just-described apparatuses cannot be effectively used in reclaiming articles of manufacture that have metallic elements encased within vitreous bulbs or housings. To use the reed switch example again, these prior art devices and methods are not suitable because they would tend not only to shatter the vitreous bulbs but also to mangle the metallic switch blades themselves. These blades, however, typically have a layer of gold coated upon an iron-cobalt-vanadium substrate in their areas of mutual contact. Thus, after the blades have been removed from the vitreous bulb material they need to be further processed in order to extract their gold content from their alloy content. This may be done by the conventional process of placing the blades within a wire mesh cylinder and rotating it in a cyanide stripping solution. However, if the blades themselves have been badly mangled portions of them will have become inaccessible by the stripping solution so that following the stripping process some of the gold will remain unreclaimed on the blades.
Thus a method of reclaiming component materials of an article of manufacturing having a metallic element encased within a brittle bulb remains desirable which does not significantly effect the structural configuration of the metallic elements themselves. It is to this task to which the present invention is primarily directed.